刚地弓形虫(Toxoplasma gondii)不同地理株对钴^(60)丙线敏感性的比较研究

COMPARISON OF RADIOSUSCEPTIBILITY OF TOXOPLASMA STRAINS OF DIFFERENT GEOGRAPHICAL ORIGIN TO (60)~CO GAMMA IRRADIATION

对中国NT株弓形虫和美国的ME—49株及TS—2株弓形虫的包囊进行了抗丙线耐受性的比较，试验采用上述三株弓形虫包囊为材料，分设0．4、0．5、0．6、0．7、1．OKGy丙线剂量组和不经照射处理的对照组。通过感染小鼠和幼猫的生物学检测，求得使包囊丧失感染性的丙线剂量，得出不同株包囊对丙线的敏感性。结果表明：丙线控制中国NT株的最小有效剂量为0．55KGy，控制ME—49株和TS—2株的感染性的最小有效剂量为0．60KGy。两者接近，提示这三个地理株的弓形虫包囊对钴60丙线的敏感性虽略有差异，但其差异并不明显。

Resistance of Chinese NT Toxoplasma strain to 6oCo gamma irradiation was compared withthat of American ME- 49 and TS -- 2 strains in this study. Toxoplasma cysts in the mouse brain tissues wereused as material in the experiments and irradiated at doses of 0. 4,0. 5, 0. 6, 0. 7, 1. OKGy,separately. Unirradiatedcysts were used in the control group. The loss of infectivity of Toxoplasma gondii cysts and the susceptivity togamma irradiation were confirmed by bioassay in mice and kittens infected with irradiated or nonirradiated cystsof I. gondii. Results showed the minima effective dose(MED) to be 0. 55KGy and for American ME--49 and TS-- 2 strains,0. 60KGy. This suggests that the difference of radio susceptibility should appear between the ChinsesNT strain and US ME-- 49,TS 2 strains, but it is not significant.